Which waves require a material medium for transmission? a.) light waves b.) radio waves c.) sound waves d.) microwaves

mechanical waves require a medium

Sound waves

Explanation:

Sound wave is the only mechanical wave, which needs a medium. Other guy is lying.

d) physical means can be used to separate the components of air.

r = ρ x length / area  

ρ = r x area / length  

ρ is in ohm-meters  

in basic units, it is m³kg/s³a²  

i think this is it.